1. Field
Aspects of one or more embodiments according to the present invention relate to an energy storage system and a controlling method thereof.
2. Description of Related Art
As environmental destruction, resource depletion, etc., become serious problems, interest in a system capable of storing energy and efficiently using the stored energy has been increased. In addition, interest in renewable energy, which does not generate pollution or generates little pollution in a development process, has been increased. An energy storage system that interconnects an existing grid, a renewable energy source, and a battery system that stores power has been researched and developed to cope with today's environmental changes. The energy storage system has various operation modes according to conditions of the renewable energy source, the battery system, the grid, and a load, so that transitions among the operation modes should be stably performed.